40 Gardening 
by a group of cells multiplying and enlarging very 
rapidly. Other cells build the stem in the same way. A 
branch of the stem or root is formed by a number of 
cells multiplying and growing out to make the branch; 
leaves, flowers, and all other parts arise from groups of 
cells that divide rapidly and push out beyond the cells 
about them. In this way new parts are formed. They 
are built from parts that already exist by the multipli- 
cation and enlargement of groups of cells. 
Regions of growth in a plant. Growth causes stems 
and roots to increase in thickness, and there is very rapid 
growth in the ends of branches which causes them to 
increase in length. Young leaves and other parts that 
are just being formed are also places where rapid growth 
is taking place. 
Stages in the life of a plant. A garden plant like a 
radish, a carrot, or a bean does not continue to grow 
indefinitely. It goes through the stages of its develop- 
ment, completes its life, and then dies. From the point 
of view of the gardener the life of a garden plant like a 
carrot consists of (1) a seed stage, (2) a nursling stage, 
(3) a building stage or stage of rapid growth, and (4) a 
stage of storing food and maturing seed. 
In the seed stage the little plant is almost completely 
inactive or dormant. We say it is in the “ resting con- 
dition.” It respires very slightly. It does not grow. 
In the nursling stage the plant begins to grow. At 
first it lives entirely on the food stored in the seed. But 
in small seeds like that of the carrot the supply of food is 
scant and the little plant must soon depend on the food 
it manufactures for itself. In the nursling stage a seed- 
